Psychometric Properties of a Short Alexithymia Scale (SAS-3) in the German General Population

Abstract

The literature on alexithymia has multiplied in recent decades as the construct has important implications for mental health. The so far used inventories are of limited use in epidemiological research, primary care, and other clinical settings where time and effort are important factors in assessment. Based on items of the authorized German version of the Toronto Alexithymia Scale, the aim of this study was to develop an ultra-short questionnaire for a condensed and unidimensional assessment of alexithymia. Criteria for the abbreviated scale were: (a) one-dimensionality (necessary to calculate a global score), (b) one item from each of the originally postulated dimensions, and (c) no reverse-coded items (to avoid method artifacts). Data were drawn from two nationwide representative population surveys in Germany: a survey conducted in 1996 to develop the SAS-3 (N=2.047); and a survey conducted in 2013 (N=2.508) for the evaluation and calculation of SAS-3 percentiles. Reasonable correlations between the SAS-3 and the PHQ-2, the GAD-2, and the GBB-8 were observed. Based on a confirmatory factor analysis, the one-dimensionality of the SAS-3 could be confirmed, achieving very good fit indices. An additional invariance analysis regarding gender and different age groups resulted in (partial) strict invariance for the different multi-group analyses. Percentile ranks for SAS-3 sum score are reported stratified by gender and by age groups. The SAS-3 appears to be suitable in epidemiological research and other instances requiring an economical assessment of alexithymia.